A recent study published in an American scientific journal estimated that there has been 6.3 billion tons of plastic waste accumulated worldwide since 1950. The Mainichi Shimbun answers questions readers may have about plastic waste and recycling efforts in Japan and overseas.
Question: I was surprised to hear that only 9 percent of the 6.3 billion tons of plastic waste had been recycled. Can you explain?
Answer: That's the estimate released in the scientific journal Science Advances by a team led by researchers from the University of Georgia. The use of plastic made from petroleum in various products began to spread widely during that time. Since processing plastic is simple and convenient, there are many different types of the material. However, when those different types are mixed together, the weakening of the material and a variety of other technical issues face the reuse of plastics. Because of this, not much progress has been made in effective recycling.
Q: What is the situation like in Japan?
A: Plastic recycling is generally divided into three different types: material, chemical and thermal. Material recycling reuses the plastic, thermal recycling burns it for energy and chemical recycling uses the raw materials for industrial purposes. In thermal recycling, the plastic is used as an ingredient for solid fuel, and the heat at the time of combustion is used to generate electricity or heat swimming pools. The national recycling rate using all three methods was 83 percent in 2015.
Q: Can thermal recycling also be used abroad?
A: Not exactly. Because plastic waste burns at a very high temperature, it causes damage to the incinerator. On top of that, there are many other issues, such as the risk of dioxin emissions. Overseas, most plastic waste is buried in landfills or simply discarded in nature, but no detailed statistics exist. The Tokyo-based Plastic Waste Management Institute is teaming up with other associations in the United States and across Europe to survey the current condition of plastic recycling mainly in developing nations.
Q: Is there anything we can do about the problem?
A: The first step is to reduce the amount of waste you personally produce. Properly separating recyclables from other trash is also extremely important. The institute requests that Japan take the lead in providing an example of good recycling procedures, and work to further increase Japan's recycling rate. (Answers by Suzuko Araki, Science & Environment News Department)